Obstetrics 1 Flashcards
What USS measurement is most useful for fetal gestation estimation earlier on in pregnancy (9-14 weeks, so for booking scan)?
Crown rump length
What fetal measurements are used later on in pregnancy, so from 14 weeks onwards?
Head circumference, fetal abdominal circumference
What is parity?
Number of potentially viable births >24 weeks
Parity score?
Para = x + yx = number of births over 24 weeks, stillbirth or normal etc.y = miscarriages, ToPs
What is gravidity?
Number of times been pregnant including current pregnancyE.g. G6 P3+2
FLIPPERBUS?
Fundus (SFH)LIe and liquor - feel all roundPresenting PartEngagement Rate and auscultation BPUrineSwelling
When is the uterus first palpable during pregnancy? When might this be earlier?
12-14 weeksEarlier in multiple pregnancy
At what gestation is fundus of uterus roughly umbilical level? What implications does this have for SFH?
20 weeksFrom that point, SFH roughly correlates to gestation +/- 2cm
Discuss engagement of fetal head?
5/5 palpable = fully above pelvic brim, not engaged3/5 = generally engaged
How many routine antenatal visits would a nulliparous woman have?
10
How many routine antenatal visits would a multiparous woman have?
7
Normal folic acid supplementation?
400micrograms per day til > 12 weeks
Specific examples of food poisoning that can affect pregnant woman badly?
Listeriosis - milkSalmonella - chicken, eggs
When should booking visit be done?
10-12 weeks
What is the combined test for Down’s syndrome screening?
Nuchal translucencyPAPPABhCG
What infections need to be screened for at booking visit?
BBVs e.g. Hep B, HIVSyphillis RubellaSTIs - chlamydia, BV, gonorrhoeaAsymptomatic bacteruria
What non-infectious conditions need to be enquired about at booking visit?
Haemaglobinopathies and anaemia Clotting dysfunctionsPre existing disease, e.g. CardiacRhesus status
When is the anomaly scan done? What are you looking for?
18-20 weeksNTDs +/- fetal echocardiography
When is rhesus anti-D routinely given prophylactically during pregnancy?
28 weeks and then 32 weeks
What is assessed at 36 week visit?
USS for fetal presentation - offer ECV if breech
When does early morning sickness often resolve in normal pregnancy?
By end of first trimester, 16-20 weeks
What is Naegele’s rule?
EDD = LMP + 9 months + 7 days
What yeast infection are pregnant women more susceptible to?
Candidiasis (thrush)
5 blood tests associated with Down’s syndrome screening?
BhHCGPAPPOestriolInhibin AAlpha FetoProtein
What USS marker is used in Down’s syndrome screening?
Nuchal translucency
What is amniocentesis and when is the earliest it should be done?
US guided removal of amniotic fluidEarliest 15 weeks
What 3 types of disease can amniocentesis be used to investigate?
Chromosomal abnormalityInfectionInherited disease
Which has a higher miscarriage rate, amniocentesis or CVS?
CVS
What is chorionic villous sampling? Earliest it can be done?
Trophoblast (placental) biopsyEarliest 11 weeks
What is CVS especially good at detecting?
Chromosomal abnormalities
2 major RFs for Down’s syndrome?
High maternal agePreviously affected baby
What signs of Down’s syndrome may be visible on USS?
Nuchal translucency Cardiac abnormality (tricuspid regurge)Short nasal bone
What are the 4 constituents which constitute the combined test for Down’s syndrome?
Maternal ageNuchal translucencyBhCGPAPP
What blood markers are raised in Down’s syndrome screening?
BhCGInhibin A
What blood markers are reduced in Down’s syndrome screening?
PAPPOestriolAlpha FetoProtein
What is Edwards syndrome?
Trisomy 18
What is trisomy 18?
Edwards syndrome
What is trisomy 13?
Patau’s syndrome
What is patau’s syndrome?
Trisomy 13
What is Klinefelters syndrome?
47 XXY - infertile males
What chromosomal abnormality commonly causes infertility in males?
Klinefelters 47XXY
What is turners syndrome?
45XO - infertile females
What chromosomal abnormality commonly causes infertility in females?
Turners 45XO
What blood marker is raised in NTDs?
Alpha FetoProtein
What congenital abdominal wall defect often occurs in the absence of any other abnormalities?
Gastroschisis
How do congenital GI defects often present antenatally?
Polyhydramnios - impaired swallow
What GI defect is common with Down’s syndrome?
Duodenal atresia
What is fetal hydrops?
Fluid accumulation in 2 or more fetal compartments e.g. Skin oedema and pleural effusion
What are the 2 classifications of causes of fetal hydrops?
Immune or non-immune
Major immune cause of fetal hydrops?
Ab immunisation incl Rhesus
5 main non-immune causes of fetal hydrops?
Chromosomal e.g. Down’sStructural - pleural effusionsCardiac including arrhythmiasAnaemia - PV B19 infection, a thalassaemia Twin-twin transfusion syndrome
Maternal causes of polyhydramnios?
DMRenal failure
Fetal causes of polyhydramnios?
Upper GI obstructionChest abnormalitiesMyotonic dystrophy
What might be the cause of polyhydramnios in multiple pregnancy?
TTTS
Potential problems caused by polyhydramnios?
Preterm labourAbnormal lie and presentation
What medication can reduce fetal fluid output and therefore ease polyhydramnios?
NSAIDs
What are the major long term complications of maternal CMV infection?
Severe neurological sequelae e.g. Hearing, visual, mental impairment
What can early pregnancy rubella infection cause?
Fetal deafnessCongenital cataractsCardiac diseaseMental retardation
Can women have the rubella vaccine in pregnancy?
No - it’s a live vaccine
What 2 implications can maternal BV have on pregnancy?
Preterm labourLate miscarriage
What can maternal chlamydia cause in pregnancy?
Neonatal conjunctivitis
Implications of GBS infection in pregnancy?
Often asymptomatic bacteruriaHowever can cause PPROM, neonatal sepsis (meningitis or pneumonia)
Implications of HBV infection in pregnancy?
Vertical transmission is possible and 90% of infected neonates become chronic carriers
5 major antenatal risks of maternal HIV infection?
Pre-eclampsiaGDMStillbirthIUGRPremature labour
What should be avoided postnatally in HIV infected mothers?
Breastfeeding
What bacteria is traditionally responsible for puerperal sepsis?
GAS (strep pyogenes)
What can GAS infection cause in mothers?
Puerperal sepsis
4 early pregnancy events which may be ‘sensitising’ in terms of Rhesus factor?
ToPEctopicERPCPV bleed
Procedure related to breech which may be a sensitising event?
ECV
When is rhesus screening acted upon in pregnancy?
To any rhesus negative woman:Within 72 hours of any potentially sensitising event including delivery if neonate positiveAt 28 weeks
Other important rhesus antibodies besides D?
C, E and Kell
6 differentials for antepartum haemorrhage?
Placenta praeviaPlacental abruptionBloody showGenital tract pathologyVasa praevia ruptureUterine rupture
What is an antepartum haemorrhage?
Bleeding from the genital tract > 24 weeks
4 RFs for placenta praevia?
Multiple pregnancyMultiparityScarred uterusAge
Presentation of placenta praevia?
Intermittent painless bleeds which may become constant and heavy over several weeks
What is placenta accreta? What normally causes it?
Non-separation of the placenta from uterine wall at birthOften due to scarred uterus - prev CS
If a placenta is found to be low lying at 20 weeks, when should it be rescanned to exclude placenta praevia?
32 weeks
5 RFs for placental abruption?
Pre-eclampsia or maternal HTNIUGRPrevious abruptionMaternal smokingMultiple pregnancy and multiparity
How does placental abruption present?
Painful bleeding PV, degree of which doesn’t necessarily reflect extent of bleed
What is the difference between a concealed and revealed placental abruption?
Concealed = pain no bloodRevealed = pain and blood
What may be found on obstetric exam in placenta praevia vs abruption?
Praevia - abnormal lie, breech, high fetal headAbruption - tender, woody hard uterus
3 genital tract pathologies that may cause antepartum haemorrhage?
EctropionPolypsCancer
What is the typical presentation of vasa praevia rupture?
Painless, moderate PV bleed around time of amniotomy or spontaneous ROM
What might a painless bleed just after amniotomy or ROM indicate?
Vasa praevia rupture
What is the normal lie in pregnancy?
Longitudinal
What 2 presentations can result from a longitudinal lie?
CephalicBreech
In what group of babies is abnormal lie the biggest problem?
Preterm babies
What are the 3 groups of reasons for an abnormal lie or breech?
Too much room to moveNo room to moveFactors preventing engagement
‘Too much room to move’ causes of abnormal presentation?
Polyhydramnios High parity (lax uterus)
What does having too much room to move in the uterus often result in?
An unstable lie
‘No turning’ causes of an abnormal lie of breech?
Oligohydramnios Multiple pregnancyUterine abnormality e.g. Fibroids
Factors preventing engagement resulting in an abnormal lie or breech?
Placenta praeviaFibroidsPelvic tumoursUterine deformity
What 2 things can an unstable lie suggest?
PolyhydramniosLax uterus (multiparity)
Complications of abnormal lie or breech?
Failure to progress in labourUterine ruptureUmbilical cord prolapse
What 2 things need to be excluded first when investigating abnormal lie at term?
Polyhydramnios Placenta praevia
3 types of breech?
ExtendedFlexedFooting
What type of breech is most common?
Extended
2 RFs for breech presentation?
Previous breechIUGR
What symptom is relatively common in breech?
Epigastric discomfort
What technique is used to turn round a breech baby?
ECV
When can ECV be done after?
37 weeks
What 2 things need to be done straight after ECV?
Give anti DDo a CTG
What 2 things are used to aid ECV?
US guidanceGive a uterine relaxant (tocolytic)
What is the purpose of doing an ECV?
To reduce the need for CS or vaginal breech delivery
In what 4 conditions is ECV less likely to work?
Nulliparous womanEngaged breechObese womenOligohydramnios
5 major contraindications to ECV?
APHFetal compromiseMultiple pregnancyROMIf subsequent vaginal delivery contraindicated e.g. Placenta praevia
Is a previous CS a contraindication to ECV?
Nope
Is a CS or vaginal breech delivery safer?
CS
Between what gestations is defined as preterm delivery?
24-37 weeks
Before what gestation do the majority of problems occur in preterm delivery?
34 weeks
2 major metabolic complications of prematurity?
HypothermiaHypoglycaemia
5 conditions that are more common as a result of prematurity?
Cerebral palsyNecrotising enterocolitisNRDS/BPDIntracranial haemorrhagePDA
Major maternal complication of preterm labour?
Infection - endometritis
In the castle analogy, what are the 6 mechanisms of preterm labour?
Too many defendersDefenders jump outPoor castle designCastle walls are weakAttackers get through wallsAttackers get in from elsewhere
Castle analogy: too many defenders?
Multiple pregnancy Polyhydramnios
Castle analogy: defenders jump out?
Fetal survival response - fetal distressChorioamnionitis Pre eclampsiaIUGRAbruptionAPH
Castle analogy: poor castle design?
FibroidsUterine malformationMaternal agePMH of premature labour
Castle analogy: weak walls?
Cervical incompetence e.g. Following LLETZ
Castle analogy: enemy breaks down walls
Infection which may be us clinicalBV, GBC, Trichomonas, chlamydiaChorioamnionitis - offensive liquor
Castle analogy: enemy gets in from elsewhere?
UTIPoor dentition
